Too easy.
K-Mart, hands down, since the question was who do you expect the most out of. We, as fans, HAVE to be expecting Kevin to carry a similar load as he did last year, bare minimum, and maybe a bit more. If he doesn't, the coming season will be even worse than most expect.
I expect him to be re-signed shortly to a longer term deal, so the team is going to be committing some hefty bucks to his continuing what he started mid-season 2 years ago and extended last season.
If Theus lets the team run, though, it will play into Kevin's strengths, and in such a scenario, I can see him averaging 5-10 points more per game for us than he did last year. And given that we are in rebuilding mode (or perhaps about to enter rebuilding mode, since Geoff hasn't made any true rebuilding moves yet), I would much rather lose 115-110 with an exciting up tempo game than lose 90-75 with the same miserable view as last season.